Hello, although this reply is well out of date, I hope someone that may
be encountering this problem may come across this post and find it very
helpful. First, *Do you have Norton AntiSpam or Norton Internet
Security? If so, this will definitely help you out.* Yahoo serves
their scripts from the same URL as their ads. The ad filtering element
of the firewall filters the voice object and popup object of Yahoo! Chat
2.0 as an advertisement. The following link will help you through the
process of configuring your ad blocking. It is just as easy to turn ad
blocking off as well. A very important step to pay attention to, is to
delete your temporary internet files after you have either configured
ad blocking or turned it off. Hope this helps, here is the link:
http://www.helpbytes.co.uk/dhtmlno.php